Question

a linear set of points with a unique starting point and extending infinitely in one direction
what term matches the definition?
a ray
b line
c segment
d perpendicular bisector

Explanation:

A ray is defined as a linear set of points with a unique starting point (endpoint) and extends infinitely in one direction. A line extends infinitely in both directions. A segment has two endpoints and is of finite length. A perpendicular bisector is a line that is perpendicular to a segment and bisects it.

Answer:

A. Ray